A celestial-aided navigation system is used to correct for errors, such as drift, in inertial sensors in an inertial navigation system in vehicles such as satellites. One example of a celestial-aided navigation system is a star tracker system. A star tracker system is an optical device used to determine location based upon the location of at least one celestial body, e.g. a star or planet, and determines a two dimensional reference frame indicating the position of the celestial object, e.g., in terms of a polar or Cartesian coordinate system.
It is desirable for a star tracker system to have as wide as possible field of regard to ensure that identifiable celestial bodies can be detected by the system. However, as the star tracker system's field of regard increases, optical aberrations occur, e.g. that cause incident light to be projected on a curved plane. However, image sensors, upon which such light is projected, are flat. As a result, such light either may not be detected by the star tracker system, or star tracker system measurements may be erroneous.